class Swan:
    ''''天鹅类'''
    _neck_swan_ = '天鹅脖子长'
    def __init__(self):
        print('_init_():',Swan.__init__swan)
wildswan = Swan()
print('直接访问：',wildswan._neck_swan_)
        

class Swan:
    ''''天鹅类'''
    _wing_swan = '天鹅脖子很长'
    def __init__(self):
        print('_init_():',Swan._neck_swan)
wildswan = Swan()
print('加入类名:',wildswan.__Swan__neck_swan)
print('直接访问:',wildswan.__Swan__neck_swan)
            